Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
George Jean
   2. Issuer Name and Ticker or Trading Symbol
ACCELERON PHARMA INC [XLRN] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O ADVANCED TECHNOLOGY VENTURE, 500 BOYLSTON STREET, SUITE 1380		 3. Date of Earliest Transaction (Month/Day/Year)
12/15/2017
(Street)

BOSTON, MA 02116		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 12/15/2017   S   105,122 (1) D $ 35.73 (2) 0 I See footnote (3)
Common Stock               1,250 D  

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
George Jean
C/O ADVANCED TECHNOLOGY VENTURE
500 BOYLSTON STREET, SUITE 1380
BOSTON, MA 02116		   X      

Signatures

 /s/ Jean George   12/18/2017
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Includes 98,674 shares, 3,959 shares, 1,902 shares and 587 shares of common stock sold by Advanced Technology Ventures VII, L.P. ("ATV VII"), Advanced Technology Ventures VII (B), L.P. ("ATV VII B"), Advanced Technology Ventures VII (C), L.P. ("ATV VII C") and ATV Entrepreneurs VII, L.P. ("ATV VII E"), respectively.
(2) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $35.99 - $36.10, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.
(3) ATV Associates VII, L.L.C. ("ATV A VII") is the general partner of ATV VII, ATV VII B, ATV VII C and ATV VII E and exercises voting and dispositive authority over the shares held by ATV VII, ATV VII B, ATV VII C and ATV VII E. Jean George is a managing director of ATV A VII and exercises voting and dispositive decisions of ATV A VII collectively with each of four other managing directors. Ms. George disclaims beneficial ownership of these securities and this report shall not be deemed an admission that she is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of her pecuniary interest therein.

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